What is the ruling on one who drinks alcohol until the end of Sha’ban, then fasts Ramadan, and then returns to drinking thereafter, knowing that he does not pray in Ramadan?

Drinking alcohol is a major sin. Abandoning prayer while denying its obligation or considering its abandonment permissible is an act of disbelief (kufr) by consensus. Scholars have differed regarding one who abandons prayer out of laziness. Most of the early scholars (Salaf) held the view that it is an act of disbelief, and this is the preponderant opinion due to the authentic texts and statements of the Companions supporting it. The majority of jurists, however, held the view that it is not an act of disbelief. According to the preponderant opinion that abandoning prayer is an act of disbelief, his fasting is of no benefit to him, and he must repent, cease drinking alcohol, and resume prayer. According to the opinion of the majority, his fasting is valid, but he incurs a great sin by abandoning prayer.